The present invention relates to a filtering device for utility sinks in aircraft in accordance with the preamble of claim 1.
Clogged sinks in aircraft, especially jet planes, constitute a major problem for airline companies throughout the world.
Due to civil aviation authority requirements, it is common practice for cabin personnel prior to landing to pour all remains from meal service, e.g., coffee, tea, orange juice, milk, etc., into the utility sink. The drainage outlet from the sinks in aircraft is usually led via a pipe2 from the sink to the outside of the fuselage. Due to the considerable pressure difference between the inside and outside of the fuselage, this drainage pipe is very thin and therefore may easily become blocked. Because of the major temperature variations existing between the inside and the outside of the fuselage, the last section of the conduit prior to the outlet on the outside of the fuselage is provided with a heating element to prevent its becoming frozen. This heating element usually has such a high temperature that a portion of the components in the waste fluid can easily become burned onto the wall of the pipe and, in time, clog up the pipe.
If the drain from the utility sink becomes clogged, there have been a number of instances where leakage from such sinks has resulted in major corrosion problems on the aircraft fuselage. In addition, delays could occur in aircraft departure due to the necessary work involved in opening clogged drains. These problems could result in major costs for the airline companies.
The purpose of the present invention is therefore to provide a filter device which effectively removes particulate material from the waste fluid so that the risk of clogging of the drain pipe is substantially reduced. Another objective of the present invention is to provide a device which breaks down fatty compounds in the waste fluid, so that these compounds do not burn solidly onto the pipe wall in the part of the drain pipe that is provided with a heating element.
This is achieved according to the present invention by a filter device for placement in a utility sink in an aircraft for filtering particulate material, and for dissolving and/or taking up fatty compounds from the waste fluid, characterized in that the device comprises a basin having one or more bottom outlets and a filter element located at the bottom of the basin, which basin has a shape adapted to the shape of the sink.
The bottom outlet is preferably made up of a plurality of through-going apertures.
The filter element consists preferably of a porous plastic material or wire netting web coated or impregnated with an enzyme- and/or soap-containing compound.